Steam-pressure gage



(No Model.)

M; MONBIL.

STEAM PRESSURE GAGE.

Patented May 22,1883.

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UNITED STATES PATENT OFFICE.

MURDOCK MCNEIL, OF EAST CAMBRIDGE, ASSIGNOR OF ONE-FOURTH TO RICHARD S. SMITH, OF BOSTON, MASSACHUSETTS.

STEAM-PRESSURE GAGE.

SPECIFICATIO forming part of Letters Patent No. 278,164, dated May 22, 1883.

Application filed October 25, 1882. (No model.)

To all'whom it may concern:

Be it known that I, MURDocK MGNEIL, of East Cambridge, in the county of Middlesex, of the State of Massachusetts, have invented a new and useful Improvement inSteam-Pressure Gages; and I do hereby declare the same to be described in the following specification and represented in the accompanying drawings, ot' Which- Figure 1 is a front view, and Fig. 2 a vertical and longitudinal section, ot' the portion ot' a pressuregage containing my invention, the nature of which is delined in the claim hereinafter presented.

The improvement is to prevent the helical or volute spring ot' the gage from becoming choked by the elastic septum or disk, against which the steam presses or directly acts, such septum heretofore generally resting immediately against the convex' side ot' thevolute or helical spring.

A. In Fig. 2 ofthe drawings, VA denotes the arched helical or volute spring, and B its sustaining-cup, provided with a cap or cover, C, Whichis screwed upon such cup, and with it constitutes an inclosing-case for parts to be described. .ThespindleD,thatextends through the spring, has fixed upon itconceutrically, and with respect tothe spring in-manner as shown, a disk, E, provided with a cylindrical shoulder, F, extending from it concentrically. Surrounding the disk is an annular cover, G, having at its middle a circular opening, a., larger in diameter and to receive the shoulder F. Resting against the cover Gr, and held firmly tosuch and the shoulder F by the cover C, is the elastic disk or septum I, of vulcanized india-rubber. There is to the coverC an induct, b, for admission ot the steam into the inclosing-case and to the septum, and there is to the cup B a hollow neck, c, which connects it with the dial-case of the gage, the spindle D being suitably adapted to the mechanism for working the index-hand of such gage. The cover Gr, at its edge, dts into an annular groove, y, in the case and against a packing, arranged in such grooves, such cover being forced closely against the said packing by the coverCwhen screwed on the cup B.

From the above it will be seen that when the steam presses upon the elastic septum a portion of such septum will be pressed into the space immediately around the shoulder F and upon such shoulder, and will crowd the disk E against thespring at the central convolution or part ofthe latter. By means of the said disk E and theperforated cover Gr, the spring becomes completely insulated from the elastic septum, which, not resting against the spring, cannot be forced betweeuits coils so as tochoke them and becomeinjured by them.

I claimy In combination With the pressure-gage, arched helical spring, and. its spindle, and their elastic septum, arranged in an inclosingcase, as set forth., the disk and its shoulder applied to the said spindle, and the perforated cap arranged in such case and with the spindie and septum, substantially as set forth.

MURDOCK MCNEIL.

Witnesses:

RH. EDDY, S. N. PIrER. 

